1. Field of the Invention
The present invention relates to a substrate connecting connector which comprises an anisotropic conductive sheet and electrically connects a printed wiring board to an electronic device mounted on top of the printed wiring board, and relates to a semiconductor device socket, a cable connector, and a board-to-board connector each having the substrate connecting connector.
2. Description of the Related Art
Semiconductor devices as electronic devices mounted on electronic equipment and the like are generally subjected to tests using semiconductor device sockets for removing latent defects before the semiconductor devices are mounted, or the semiconductor devices are generally mounted on electronic equipment with the semiconductor device sockets interposed therebetween. Such semiconductor device sockets used in the tests or mounting are generally referred to as IC sockets. The IC sockets are provided on printed wiring boards (test boards or mounting boards), for example, as shown in Japanese Patent No. 2,904,193.
In the case of a semiconductor device socket provided in a transmission path where a differential signal and the like are transmitted at communication rates in a comparatively high frequency range, for example, 10 Gbps or more, it is known that the IC socket's performance of transmitting signals in a comparatively high frequency range is enhanced by adjusting impedance matching in the IC socket to improve the performance of transmitting signals in a comparatively high frequency range and reducing the inductance of each contact terminal of the IC socket by minimizing the length between a contact point of a movable terminal portion and a proximal end of a soldered fixed terminal portion in the contact terminal. Meanwhile, there is a case where the proximal ends of the soldered fixed terminal portions of the contact terminals are fixed directly to contact pads of the printed wiring board. In this case, corrosion-resistant gold plating is provided on the contact pads of the print wiring board, but it is difficult to make a coating thickness of the gold plating partially thick in the contact pads. Accordingly, if the gold plating in the contact pads of the printed wiring board has comparatively small thickness, for example, the reliability in electrical connection and the durability may be poor in some cases.
To address these problems, as shown in Japanese Patent No. 2,904,193 and Japanese Patent Laid-open No. 2004-128156, a semiconductor device socket in which a semiconductor device provided in the semiconductor device socket is electrically connected to the printed wiring board through an anisotropic conductive sheet provided directly or indirectly on the printed wiring board, has been proposed. When the semiconductor device socket is provided with the anisotropic conductive sheet and the semiconductor device is electrically connected, the conductive portions formed in the anisotropic conductive sheet are pressed with predetermined pressure.